As compared to one-dimensional codes, two-dimensional codes are capable of storing more information in a smaller area and have superior data efficiency; therefore, two-dimensional codes are widely utilized in a variety of applications, such as inventory management and Web derivatives using mobile phones.
A two-dimensional code comprises position detection patterns of a prescribed form for detection of the positional relationship of its photographed image. In such a two-dimensional code, the position detection patterns each have a form that can be easily distinguished from other parts. When a two-dimensional code is analyzed, on its photographed image, the position detection patterns are detected and conversion is carried out based on their positional relationships. Detection of the position detection patterns is a fundamental process of the analysis and, since the code cannot be recognized without the detection of the position detection patterns, it is a critical element for the accuracy of the code analysis to configure the position detection patterns in an easily recognizable manner.
As a conventional two-dimensional code, the two-dimensional code disclosed in Patent Literature 1 is known.